What we are studying
This is a research study to test a drug (study drug) that has not yet been approved for sale. The study drug and efavirenz belong to the class of medications known as non-nucleoside reverse transcriptase inhibitors (NNRTIs), and TRUVADA™ belongs to the class of medications known as nucleoside/nucelotide reverse transcriptase inhibitors (NRTIs). Both efavirenz and TRUVADA™ are medications prescribed for the treatment of HIV infection. This is a 2-part study (Part I and Part II). You will participate in only one part (Part I or Part II) of this study.